Credit

Caption

Interaction between magnetic poles. Illustration of bar magnets showing magnetic attraction and repulsion (arrows) between the magnetic poles. Magnetism is a property of ferromagnetic metals (such as iron, nickel and cobalt) caused by the alignment of the spins of the electrons in the metal. By convention, the resulting magnetic poles in a magnet are labelled north (N) and south (S), here represented as red and white. Opposite poles attract (bottom), while poles of the same polarity repel each other (middle and top).